Since the creation of the material world, everyone has been trying to attain a permanent life, but the laws of nature are so cruel that no one has been able to avoid the hand of death. No one wants to die, nor does anyone want to become old or diseased. The law of nature, however, does not allow anyone immunity from old age, disease or death. Nor has the advancement of material knowledge solved these problems. Material science can discover the nuclear bomb to accelerate the process of death, but it cannot discover anything that can protect man from the cruel hands of old age, disease and death.
From the Purāṇas we learn of the activities of Hiraṇyakaśipu, a king who was very much advanced materially. Wanting to conquer cruel death by his material acquisitions and the strength of his nescience, he underwent a type of meditation so severe that the inhabitants of all the planetary systems became disturbed by his mystic powers. He forced the creator of the universe, the demigod Brahmā, to come down to him. He then asked Brahmā for the benediction of becoming amara, by which one does not die. Brahmā said that he could not award the benediction because even he, the material creator who rules all planets, is not amara. As confirmed in the Bhagavad-gītā (8.17), Brahmā lives a long time, but that does not mean he is immortal.
Hiraṇya means "gold," and kaśipu means "soft bed." This cunning gentleman Hiraṇyakaśipu was interested in these two things-money and women-and he wanted to enjoy them by becoming immortal. He asked from Brahmā many benedictions in hopes of indirectly fulfilling his desire to become immortal. Since Brahmā told him that he could not grant the gift of immortality, Hiraṇyakaśipu requested that he not be killed by any man, animal, god or any other living being within the 8,400,000 species. He also asked that he not die on land, in the air or water, or by any weapon. In this way Hiraṇyakaśipu foolishly thought these guarantees would save him from death. Ultimately, however, although Brahmā granted him all these benedictions, he was killed by the Personality of Godhead in the form of Nṛsiṁha, the Lord's half-lion, half-man incarnation, and no weapon was used to kill him, for he was killed by the Lord's nails. Nor was he killed on the land, in the air or in the water, for he was killed on the lap of that wonderful living being, Nṛsiṁha, who was beyond his conception.
The whole point here is that even Hiraṇyakaśipu, the most powerful of materialists, could not become deathless by his various plans. What, then, can be accomplished by the tiny Hiraṇyakaśipus of today, whose plans are thwarted from moment to moment?
Śrī Īśopaniṣad instructs us not to make one-sided attempts to win the struggle for existence. Everyone is struggling hard for existence, but the laws of material nature are so hard and fast that they do not allow anyone to surpass them. In order to attain a permanent life, one must be prepared to go back to Godhead.
The process by which one goes back to Godhead is a different branch of knowledge, and it has to be learned from revealed Vedic scriptures such as the Upaniṣads, Vedānta-sūtra, Bhagavad-gītā and Śrīmad-Bhāgavatam. To become happy in this life and attain a permanent blissful life after leaving this material body, one must study this sacred literature and obtain transcendental knowledge. The conditioned living being has forgotten his eternal relationship with God and has mistakenly accepted the temporary place of his birth as all in all. The Lord has kindly delivered the above-mentioned scriptures in India and other scriptures in other countries to remind the forgetful human being that his home is not here in this material world. The living being is a spiritual entity, and he can be happy only by returning to his spiritual home.
From His kingdom the Personality of Godhead sends His bona fide servants to propagate this message by which one can return to Godhead, and sometimes the Lord comes Himself to do this work. Since all living beings are His beloved sons, His parts and parcels, God is more sorry than we ourselves to see the sufferings we are constantly undergoing in this material condition. The miseries of this material world serve to indirectly remind us of our incompatibility with dead matter. Intelligent living entities generally take note of these reminders and engage themselves in the culture of vidyā, or transcendental knowledge. Human life is the best opportunity for the culture of spiritual knowledge, and a human being who does not take advantage of this opportunity is called a narādhama, the lowest of human beings.